Molder s sand for steel castings



UNITED STATES PATENT OFFICE.

ALBERT TANNER, OF MELROSE PARK, ILLINOIS.

MOLDERS SAND FOR STEEL CASTINGS.

SPECIFICATION forming part of Letters Patent No. 566,486, dated August25, 1896.

Application filed February 14:, 1896. Serial No. 579,306. (Nospecimens.)

To all whom it may concern:

Be it known that I, ALBERT TANNER, a citizen of the United States,residing at Melrose Park, in the county of Cook and State of Illinois,have invented a new and useful Improvement in Molders Sand for SteelCastings, of which the followingis a specification.

My invention relates to an improvement in molders sand particularlyadapted to the making of steel castings. It is well known that theconditions prevailing in the making of steel castings differ from thosein the case of cast-iron castings, so that much difficulty isexperienced in using the processes common to the making of cast-ironcastings in casting steel. I have found that by mixing salt with the drysand a mold is formed producing a much more perfect steel casting thanis obtained from the use of the ordinary green sand. For obvious reasonsit is desirable that the sand shall be moist, as it is in this conditionmuch easier to handle and to pack into the proper form, but the use ofgreen sand in steel castings is practically impossible, because of thechilling effect upon the surface of the casting. Where salt is combinedwith and forms a component part of the molding-sand, the efiect seems tobe to preserve in the mold for a greater period the heat due to theintroduction of the molten steel, whereby the cooling of the steel andof the mold is approximately concurrent.

My invention consists, partly, in a molders sand having mixed therewith,and forming a part thereof, salt dissolved in water. It is preferred toproduce the admixture by saturating the dry sand with water in whichsalt has been dissolved.

My invention consists, further, in a composition for molders sandcomprising ordinary sand and salt together with carbonaceous dust,resinous material, and hydrocarbon oil, the three last named being usedseparately or together in the same composition, or any two of them beingused without the third; but I prefer to use them all. I find that thefollowing specific formula gives most desirable results, and in practiceI prefer for steel castings to use this formula: old dry sand, aboutseventy parts; newdry sand, about eighty parts; coke-dust, one part;plumbago, four parts; rosin, one part, the'whole being thoroughly mixedin a suitable box. Then to about two gallons of water add a half-pint ofhydrocarbon oil and a half-pound of salt, mixing thoroughly until thesalt is dissolved, and add to the dry contents of the box. The massbeing thoroughly stirred and turned over is ready for use. necessarymerely to moisten it slightly with water. In cases where heavy castingsare to be made I have found it profitable to add a small quantity ofordinary fire-brick dust.

I am aware that a facing for a core adapted particularly to makingcast-iron castings has heretofore been suggested, comprising a mixtureof coal-dust and salt, the purpose being to preserve the core and giveit rigidity, and my invention is clearly to be distinguished from thispractice, inasmuch as the salt is a component part of the molders sandand the product is as well adapted and in fact is more particularlyintended for the mold and not necessarily for the core. I am also awarethat plumbago, rosin, and coke-dust, as well .as a hydrocarbon oil, havebeen applied to the surface of a mold or core as a facing, and in someinstances plumbago and coke-dust have been mixed with the sand, and myinvention is clearly to be distinguished from any such practice.

It is found that the castings made with the composition for molders sandherein described are' more perfect in texture, cleaner, and more readilyfreed from the sand than is the case with ordinary castings,particularly steel castings made with sand, as heretofore practiced.

What I claim as new, and desire to secure by Letters Patent, is-

1. The composition for molders sand comprising sand, salt and resinousmaterial, the whole being combined substantially as described.

2. The composition for molders sand, comprising sand, salt, resinousmaterial, dry carbonaceous material and a hydrocarbon oil, the Wholebeing combined substantially as described.

3. The process of producing a molders sand, which consists in mixingsand, dry carbonaceous material and resinous material, in substantiallythe proportions named, and saturating the mass with a composition ofwater, salt and oil in substantially the proportions named, as setforth.

- ALBERT TANNER. In presence of-- J. N. HANSON, J. H. LEE.

Should it become dry, it is

